Concrete producers detail their experiences with high-performance concrete in two experimental bridge projects.
The two bridges, one recently completed in Nebraska and one under construction in Texas, used high-performance concrete in an effort to improve long-term performance. The concrete producers discuss how they were affected by, and reacted to, the bridge designer's decision to use HPC.
By definition, HPC maximizes specific concrete qualities for each project, creating a unique mix design. For bridge projects, the Federal Highway Administration proposed a system to categorize types of mixes based on eight desirable performance characteristics.
Additionally, the two projects had different goals. In Nebraska, the goal was to introduce partnering to find better approaches to road construction. In Texas, aesthetics were as important as performance. A "U"-beam shape aims to achieve design compressive strengths from 10,000 to 13,000 psi, with widely spaced beams spanning up to 135 feet.